Hot-air furnace



Patented Aug. 12, 1924.

g UNITED STATES PATENT OFFICE.

GEORGE F. ISGRIG, OF ST. LOUIS, MISSOURI, ASSIGNOR OF ONE-HALF TO JOHN Cr. SATTERFIELD, OF ST. LOUIS, MISSOURI.

j f HOT-AIR FURNACE.

Application filed. December 10, 1923.

To all whom t may concern.'

Be it known that I, GEORGE F. IsGRIG, a citizen of the United States, residing at St. Louis, Missouri, have invented a new and:

'5 useful Hot-Air Furnace, of which the following is a speoication.

This invention relates to hot air furnaces.

An object of the invention is to provide an improved hot air furnace embodying means for utilizing to the fullest extent the heat of the heated gases and products of combustion passing from the furnace to heat the air confined about the furnace.

Another objectof the invention is to provide a hot air furnace having an outlet pipe for the smoke and gas, and means for obtaining a direct draft from the furnace to the pipe or for circulating the smoke and gas through a drum to obtain maximum advantage from the hot smoke and gases to heat the air confined about the furnace.

Other objects will appear from the following description, reference being made to the drawing in which- Fig. 1 is a cross sectional view of the furnace embodying the present invention.

Fig. 2 is a vertical sectional view on the line 2-2 of Fig. 1. p

The combustion chamber 1 and the enclosing air drum 2 having pipes 3 for conducting the hot air to points of use are of usual construction.

The present invention consists of devices located between the combustion chamber 1 and the smoke outlet pipe or liue 4: for obtaining a direct draft or for retarding and circulating the hot smoke and gases to obtain maximum advantage therefrom in heating the air in the air chamber.

As shown, the combustion chamber supports at its upper end a drum comprising a lower wall 5, a side wall 6 spaced from the wall of the drum 2 and an upper wall 7 closing the upper end of the drum and opening into the outlet pipe or flue 4. The diameter of said drum is considerably greater than the diameter of the combustion cham- 'ber 1 and the opening from the combustion chamber into4 said drum is the full diameter of the top of the combustion chamber.

A baffle wall 8 rests upon a number of supports 9 which extend upwardly from kthe bottom wall 5 of the drum. The baffle wall 8 is of less diameter than the drum leaving a Serial No. 679,559.

space 10 between the drum wall 6 and the edge of said baffle wall for the passage of the smoke and heated gases when the direct communication from the combustion chamber 1 to the outlet pipe or flue 1 is closed. A hole 11 through the center of the baffle wall 8 is fully as large as the opening to the 'outlet pipe or flue 4L and is in axial. alinement therewith. The hole 11 is equipped with a slidingy damper or closure 12 supported on flanges 13 and connected with an operating rod la extending outwardly through the drum wall 6 and through the air drum 2. By means of the rod 14 the damper or closure 12 can be moved from closed to open position and vice versa. When it is desired to have direct draft the closure or damper 12 is opened. After the fire is well started and it is desired to increase the heat, the closure or damper 12 is closed thereby diverting the hot smoke and gases through the space 12 beween the drum 6 and the edge of the bafe 8.

A spiral 15 beginning at the point 16 at the edge of the hole 12 and running about three-fourths, more or less, around the space 12 and around the opening into the pipe or flue 4, has a continuing circular portion 17 forming about three-fourths of a circle within and slightly spaced from the drum wall 6. This leaves an open space 18 through which the hot smoke and gases may pass to the inside of the circular wall portion 17 and thence follow the spiral wall 15 to the opening into the pipe or flue 4L. In this way the heated smoke and gases are circulated so as to radiate the heat therefrom to the air confined in the air drum 2 about the furnace.

From the foregoing it will be seen that my invention is a simple and efficient one and obtains all of its intended objects and purposes. The structure may be-easily manufactured and assembled and the use thereof is highly advantageous as it obtains more heat from less fuel than in the case of furnaces having only direct communication from the combustion chamber to the outlet pipe or flue.

I am aware that the construction and arrangement may be varied in numerous particulars without departure from the nature and principle of the invention, and I do not restrict myself unessentially,

What I claim and desire to secure by Letters Patent is 1. In a hot air furnace, the combination with a combustion chamber and a smoke outlet flue, of a drum opening into the coinbustion chamber and into the outlet flue, a baiile Wall in the drum of greater diameter than the opening into the combustion cham-- ber spaced from the bottom of the drum and from the side Wall of the drum, and a spiral Wall upon the battle forming a tortuous passage from theedge of the baille Wall to the opening intothe outlet flue.

2. In ay hot air Ilurnace, the combination with a combustion chamber and a smoke outlet flue, of a drum opening into the combustion chamber and into the outlet flue, a baffle Wallin the drum of greater diameter than the opening'into the combustion chamber spaced from the bottom ofthe drum and from the'side wall of the drum, aspiral Wall upon the baille forming a tortuous passagey from the edge of the baffle Wall to the opening into the outlet Hue, and means for providing direct communication from the combustion chamber to the outlet flue.

3. In va hot air furnace, the combination with a combustion chamber, an outlet flue and an air drum, of a drum at the top of the combustion chamber opening into the combustion chamber' and into the outlet flue, a baille Wall supported in said drum of greater diameter than the opening into the combustion chamber and spaced from the bottom and side Walls of said second drum, and a tortuous passage from the edge of said baffle Wall to the opening into said outlet flue. n

4. In a hot air furnace, the combination with a combustion chamber, an outlet flue and an air drum, of a drinn at the top of the combustion chamber opening into the combustion chamber and into the outlet Hue, a baiie Wall supported in said drum of greater diameter than the opening into the combustion chamber and spaced from the bottom and side Walls of said second drum, a tortuous passage from the edge of said baflle Wall to the opening into said outlet Aflue, a direct passage through said baille Wall to the opening into said flue, and a device for opening and closing said passage.

GEORGE F. ISG'RIG. 

